如何在 Mule 的回滚异常策略组件中将会话变量作为参数传递给 maxRedeliveryAttempts 字段？

Question

下面是 Mule 配置 XML。

<http:listener-config name="HTTP_Listener_Configuration" host="localhost" port="8090" doc:name="HTTP Listener Configuration"/>
<flow name="testflowFlow">
    <http:listener config-ref="HTTP_Listener_Configuration" path="/test" doc:name="HTTP"/>
    <set-session-variable variableName="count" value="#[message.inboundProperties.'http.query.params'.retrycount]" doc:name="count Session Variable"/>
    <set-payload value="#[sessionVars.count]" doc:name="Set Payload"/>
    <file:outbound-endpoint path="C:\Users\y0134079\Desktop" responseTimeout="10000" doc:name="File"/>
    <set-payload value="#[sessionVars.count]" doc:name="Set Payload"/>
    <rollback-exception-strategy maxRedeliveryAttempts="#[sessionVars.count]" doc:name="Rollback Exception Strategy"/>
</flow>

我试图在 HTTP 请求的查询参数之一 (retrycount) 中传递最大重试次数。但是 maxredeliveryattempts 字段需要一个整数，并且由于提供的查询参数是一个字符串，因此构建失败，因为它无法从字符串转换为整数。对此有什么建议吗？

错误：

***** 原因：org.springframework.beans.TypeMismatchException：无法将 'java.lang.String' 类型的属性值转换为属性所需的类型 'java.lang.Integer' 'maxRedeliveryAttempts';嵌套异常是 java.lang.NumberFormatException：对于输入字符串：“[sessionVars.count]” 在 org.springframework.beans.BeanWrapperImpl.convertIfNecessary(BeanWrapperImpl.java:468) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE]***** 在 org.springframework.beans.BeanWrapperImpl.convertForProperty(BeanWrapperImpl.java:494) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.BeanWrapperImpl.convertForProperty(BeanWrapperImpl.java:488) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.convertForProperty(AbstractAutowireCapableBeanFactory.java:1464) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1423) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1159) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveInnerBean(BeanDefinitionValueResolver.java:276) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:129) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1418) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1159) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:293) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:290) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:191) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:633) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:932) ~[spring-context-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:479) ~[spring-context-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.mule.config.spring.SpringRegistry.doInitialise(SpringRegistry.java:86) ~[mule-module-spring-config-3.6.1.jar:3.6.1] 在 org.mule.registry.AbstractRegistry.initialise(AbstractRegistry.java:105) ~[mule-core-3.6.1.jar:3.6.1] 在 org.mule.config.spring.SpringXmlConfigurationBuilder.createSpringRegistry(SpringXmlConfigurationBuilder.java:135) ~[mule-module-spring-config-3.6.1.jar:3.6.1] 在 org.mule.config.spring.SpringXmlConfigurationBuilder.doConfigure(SpringXmlConfigurationBuilder.java:90) ~[mule-module-spring-config-3.6.1.jar:3.6.1] 在 org.mule.config.builders.AbstractConfigurationBuilder.configure(AbstractConfigurationBuilder.java:43) ~[mule-core-3.6.1.jar:3.6.1] 在 org.mule.config.builders.AbstractResourceConfigurationBuilder.configure(AbstractResourceConfigurationBuilder.java:69) ~[mule-core-3.6.1.jar:3.6.1] 在 org.mule.config.builders.AutoConfigurationBuilder.autoConfigure(AutoConfigurationBuilder.java:101) ~[mule-core-3.6.1.jar:3.6.1] 在 org.mule.config.builders.AutoConfigurationBuilder.doConfigure(AutoConfigurationBuilder.java:52) ~[mule-core-3.6.1.jar:3.6.1] 在 org.mule.config.builders.AbstractConfigurationBuilder.configure(AbstractConfigurationBuilder.java:43) ~[mule-core-3.6.1.jar:3.6.1] 在 org.mule.config.builders.AbstractResourceConfigurationBuilder.configure(AbstractResourceConfigurationBuilder.java:69) ~[mule-core-3.6.1.jar:3.6.1] 在 org.mule.context.DefaultMuleContextFactory$1.configure(DefaultMuleContextFactory.java:84) ~[mule-core-3.6.1.jar:3.6.1] 在 org.mule.context.DefaultMuleContextFactory.doCreateMuleContext(DefaultMuleContextFactory.java:217) ~[mule-core-3.6.1.jar:3.6.1] 在 org.mule.context.DefaultMuleContextFactory.createMuleContext(DefaultMuleContextFactory.java:76) ~[mule-core-3.6.1.jar:3.6.1] 在 org.mule.module.launcher.application.DefaultMuleApplication.init(DefaultMuleApplication.java:187) ~[mule-module-launcher-3.6.1.jar:3.6.1] ... 14 更多原因：java.lang.NumberFormatException：对于输入字符串：“[sessionVars.count]” 在 java.lang.NumberFormatException.forInputString(NumberFormatException.java:65) ~[?:1.7.0_79] 在 java.lang.Integer.parseInt(Integer.java:492) ~[?:1.7.0_79] 在 java.lang.Integer.valueOf(Integer.java:556) ~[?:1.7.0_79] 在 java.lang.Integer.decode(Integer.java:984) ~[?:1.7.0_79] 在 org.springframework.util.NumberUtils.parseNumber(NumberUtils.java:155) ~[spring-core-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.propertyeditors.CustomNumberEditor.setAsText(CustomNumberEditor.java:115) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.TypeConverterDelegate.doConvertTextValue(TypeConverterDelegate.java:455) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.TypeConverterDelegate.doConvertValue(TypeConverterDelegate.java:427) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.TypeConverterDelegate.convertIfNecessary(TypeConverterDelegate.java:181) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.BeanWrapperImpl.convertIfNecessary(BeanWrapperImpl.java:448) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.BeanWrapperImpl.convertForProperty(BeanWrapperImpl.java:494) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.BeanWrapperImpl.convertForProperty(BeanWrapperImpl.java:488) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.convertForProperty(AbstractAutowireCapableBeanFactory.java:1464) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1423) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1159) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveInnerBean(BeanDefinitionValueResolver.java:276) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:129) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1418) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1159) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:293) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:290) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:191) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:633) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:932) ~[spring-context-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:479) ~[spring-context-3.2.10.RELEASE.jar:3.2.10.RELEASE] 在 org.mule.config.spring.SpringRegistry.doInitialise(SpringRegistry.java:86) ~[mule-module-spring-config-3.6.1.jar:3.6.1] 在 org.mule.registry.AbstractRegistry.initialise(AbstractRegistry.java:105) ~[mule-core-3.6.1.jar:3.6.1] 在 org.mule.config.spring.SpringXmlConfigurationBuilder.createSpringRegistry(SpringXmlConfigurationBuilder.java:135) ~[mule-module-spring-config-3.6.1.jar:3.6.1] 在 org.mule.config.spring.SpringXmlConfigurationBuilder.doConfigure(SpringXmlConfigurationBuilder.java:90) ~[mule-module-spring-config-3.6.1.jar:3.6.1] 在 org.mule.config.builders.AbstractConfigurationBuilder.configure(AbstractConfigurationBuilder.java:43) ~[mule-core-3.6.1.jar:3.6.1] 在 org.mule.config.builders.AbstractResourceConfigurationBuilder.configure(AbstractResourceConfigurationBuilder.java:69) ~[mule-core-3.6.1.jar:3.6.1] 在 org.mule.config.builders.AutoConfigurationBuilder.autoConfigure(AutoConfigurationBuilder.java:101) ~[mule-core-3.6.1.jar:3.6.1] 在 org.mule.config.builders.AutoConfigurationBuilder.doConfigure(AutoConfigurationBuilder.java:52) ~[mule-core-3.6.1.jar:3.6.1] 在 org.mule.config.builders.AbstractConfigurationBuilder.configure(AbstractConfigurationBuilder.java:43) ~[mule-core-3.6.1.jar:3.6.1] 在 org.mule.config.builders.AbstractResourceConfigurationBuilder.configure(AbstractResourceConfigurationBuilder.java:69) ~[mule-core-3.6.1.jar:3.6.1] 在 org.mule.context.DefaultMuleContextFactory$1.configure(DefaultMuleContextFactory.java:84) ~[mule-core-3.6.1.jar:3.6.1] 在 org.mule.context.DefaultMuleContextFactory.doCreateMuleContext(DefaultMuleContextFactory.java:217) ~[mule-core-3.6.1.jar:3.6.1] 在 org.mule.context.DefaultMuleContextFactory.createMuleContext(DefaultMuleContextFactory.java:76) ~[mule-core-3.6.1.jar:3.6.1] 在 org.mule.module.launcher.application.DefaultMuleApplication.init(DefaultMuleApplication.java:187) ~[mule-module-launcher-3.6.1.jar:3.6.1] ... 14 更多信息 2016-05-03 08:13:33,029 [主要] org.mule.module.launcher.DeploymentDirectoryWatcher: ++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++ + 骡子站起来踢腿（每 5000 毫秒）+ ++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++ 信息 2016-05-03 08:13:33,239 [主要] org.mule.module.launcher.StartupSummaryDeploymentListener:

- - - 域 + - - * - - + 状态 + - - *
默认 * 已部署 *

- - - 应用程序 + - - * - - + 域 + - - * - - + 状态 + - - *
testflow * 默认 * 失败 *

Answer 1

使用#[Integer.parseInt(sessionVars.count)]

Answer 2

该属性不支持 MEL 表达式。它支持 spring 属性占位符，但不支持动态 MEL 表达式。它是在初始化而不是运行时评估的。

如何在 Mule 的回滚异常策略组件中将会话变量作为参数传递给 maxRedeliveryAttempts 字段？

How can I pass a session variable as parameter for maxRedeliveryAttempts field in rollback-exception-strategy component in Mule?

mule

mule-studio

mule-component